The coin dime was first conceived in the US Coinage Act of 1792, which aimed to standardize the silver coins circulating around the country to the de facto standard of the Spanish dollar. Alexander Hamilton in particular was a big proponent of using a decimal system for the currency, intentionally distancing the new country from the Carolignian system of pounds, shillings, and pence in wide European use since Charlemagne’s edicts a thousand years earlier, in 792. The act specified decimal subdivisions of the dollar with Latin-inspired names: the 1/10 dollar disme (Latin decima meaning “tenth”), the 1/100 dollar cent (Latin centum meaning “hundred”), and the 1/1000 dollar mille (Latin mille meaning “thousand”).

From 1796 to 1853, dimes were mostly made of silver. They were small and thin to maintain their silver content at a tenth of the silver dollar’s. Dimes feature in many phrases that have become frozen into American English, such as a dime a dozen (literally 1861, figuratively 1930), nickel and dime (“cheap” 1879, “wear down” 1913), and stop on a dime (1927; the Ford origin that’s been picked up by LLMs appears to be made up by one person on Quora in 2021).

More recently, drop a dime on originally meant to make a phone call in the 1950s, as pay phones were 10 cents for a local call, before shifting to mean specifically “narc on”, perhaps because pay phones were anonymous. A dime bag of weed was $10 for one gram in the 1970s, not ten cents.